package util;

import java.security.MessageDigest; 
 
public class Encrypt { 
 
    private static String convertToHex(byte[] data) { 
        StringBuilder buf = new StringBuilder();
        for (int i = 0; i < data.length; i++) { 
            int halfbyte = (data[i] >>> 4) & 0x0F;
            int two_halfs = 0;
            do { 
                if ((0 <= halfbyte) && (halfbyte <= 9)) 
                    buf.append((char) ('0' + halfbyte));
                else 
                    buf.append((char) ('a' + (halfbyte - 10)));
                halfbyte = data[i] & 0x0F;
            } while(two_halfs++ < 1);
        } 
        return buf.toString();
    } 
 
    public static String SHA1(String text)  { 
        try {
            MessageDigest md;
            md = MessageDigest.getInstance("SHA-1");
            byte[] sha1hash = new byte[40];
            md.update(text.getBytes("iso-8859-1"), 0, text.length());
            sha1hash = md.digest();
            return convertToHex(sha1hash);
        } catch (Exception ex)  {
            return null;
        }
    } 
}